(EN)A bed has a first frame structure (2, 5, 11, 12) and a further frame structure (6). The first frame structure has a support surface (2) for a mattress or the like, and between the two frame structures is arranged at least one pivot-arm mechanism (14) for lifting the first frame structure up from the further frame structure and to cause, at the same time, lateral displacement in the width direction of the rectangular support surface and preferably also in its longitudinal direction. In the normal positions of the frame structure, the further frame structure has at least one longitudinally extending side part (24) located inwardly of the nearest side edge (4) of the support surface, and during said lateral displacement said side edge is moved towards and over said side part. (FR)Un lit possede un premier chalit (2, 5, 11, 12) et un second chalit (6). Le premier chalit possede une surface de support (2) d"un matelas ou autre, et entre les deux chalits est dispose au moins un mecanisme a bras pivotant (4) pour separer, en le soulevant, le premier chalit du second chalit et provoquer en meme temps un deplacement lateral dans le sens de la largeur de la surface de support rectangulaire et, de preference, egalement dans le sens longitudinal. Dans les positions normales du chalit, le second chalit possede au moins une partie laterale (24) qui se prolonge longitudinalement et qui est situee a l"interieur du bord lateral le plus rapproche (4) de la surface de support; pendant ledit deplacement lateral ce bord se rapproche et passe au-dessus de ladite partie laterale.